so I run sudo nano /etc/default/grub

For improved security during file edits that require root access, it’s highly advised to use sudoedit (or sudo -e). This method is considered the standard practice to avoid the security pitfalls associated with directly invoking editors with sudo. To ensure the use of nano with sudoedit, simply set the VISUAL environment variable with export VISUAL=nano before running sudoedit . Alternatively, for a one-off command: VISUAL=nano sudoedit /path/to/file.

Please note that while sudoedit is a safer starting point, it’s not the only method available. Alternatives such as doas, doasedit, or leveraging polkit with pkexec can offer even more controlled and secure ways to manage file editing with elevated privileges. However, it’s perfectly acceptable to stick with sudoedit, as it’s a commonly trusted tool.

Be aware that direct usage of sudo nano or other editors is strongly discouraged. It bypasses important security mechanisms and can lead to inadvertent system-wide risks.

EDIT: changed VISUAL=nano sudoedit to VISUAL=nano sudoedit /path/to/file.